Liquid crystal materials containing a diphenylethane nucleus

Abstract

Novel mesomorphic substances, constituting, in certain temperature ranges, nematic or smectic liquid crystals which are compounds of the formula: ##STR1## wherein R 1 is an alkoxy group containing 1 to 10 atoms of carbon; R 2 is an alkyl group containing 1 to 10 atoms of carbon; X is Br or CN.

What we claim is: 
     
       1. Liquid crystal materials of the formula: ##STR21## wherein R 1  represents an alkoxy group having n carbon atoms (n being an integer from 1 to 10), R 2  represents an alkyl group having m carbon atoms (m being an integer from 1 to 10) and X represents bromine or the cyanide group. 
     
     
       2. Liquid crystal materials according to claim 1, wherein: R 1  =C 8  H 17  O   R 2  =C 5  H 11     X=Br.   
     
     
       3. Liquid crystal materials according to claim 1, wherein: R 1  =C 8  H 17  O   R 2  =C 5  H 11     X=CN.   
     
     
       4. A liquid crystal mixture which comprises a material of the formula of claim 1 and the para-methoxybenzoate of parapentyl phenol. 
     
     
       5. A liquid crystal mixture according to claim 4 wherein said material represents 10 percent in moles of said mixture.